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Objective To explore the value of quantitative parameters of gemstone spectral CT in the diagnosis of pulmonary embolism (PE). Methods 29 patients with PE were examined by gemstone spectral CT under GSI scanning mode.The pulmonary embolus on CTPA image were detected and the location and number of embolus were recorded.A variety of quantitative parameters of the embolic and normal areas were measured by the GSI Viewer.Paired t test was used to compare and analyze the quantitative parameters,and ROC curve was used to evaluate the diagnostic efficacy of quantitative parameters.Results 76 clots were diagnosed by CTPA in 29 patients.The iodine content,slope of energy spectrum curve and corresponding CT of 40 keV in the embolic area were significantly lower than those in the normal area (P＜0.001),there were no significant differences in water content and effective atomic number between the embolic and normal area;The ROC curve analysis showed that iodine content had the largest area under the diagnosis curve of pulmonary embolism (0.84)with the specificity of 88% and the sensitivity of 65%.The AUC could be up to 0.89 when three quantitative parameters were combined to get the ROC curve,with the sensitivity of 82% and the specificity of 90%.Conclusion Some quantitative parameters of the pulmonary embolic area are lower than those in the normal area,which indirectly reflect the abnormal blood perfusion of the embolism and provide more basis for the early diagnosis,condition assessment and evaluation of therapeutic effect of PE.
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Objective To evaluate the value of gemstone spectral imaging (GSI)and multi artifact reduction system(MARs)in re-ducing metallic implants artifacts,and find the best monochromatic images.Methods Twenty-one patients with metal implants in our hospital receievd GSI examination ,MARS reconstruction and polychromatic images(140 kVp).Eleven groups of monochromatic and MARS images were obtained from 40 keV to 140 keV every interval of 10 keV by the special GSI viewer ,respetively.Subjective image quality of two methods were assessed by 3 radiologists in consensus.For every patient one group monochromatic images and blend enery images were selected two heaviest artifacts level and no artifacts level,the CT value and the standard deviations(SD)value of the region of interest(ROI)were meatured of artifacts.Contrast-to-noise ratio(CNR)and artifacts index(AI)were also caculated and were analyzed with paired-t test.Results There was significant statistical differences of CNR between energy spectral images and blend energy images in energy level of 40 to 120 keV(P 0.05),and the optimal CNR was acquired at the energy level of 70 keV(CNR=8.75±3.28).The value of AI for two mehtods has no difference in energy level scope 40 to 60 keV(P >0.05),there was significant statistical differences of AI between energy spectral images and blend energy images in energy level of 70 to 140 keV(P <0.05),and the lowest of AI(AI=26.95±9.64)was ac-quired at 1 10 keV images.Conclusion The energy spectral CT possess superiority in decreasing the artifacts and will provide high image quality in the metal implants.Gemstone spectral CT has great significance for postoperative patients with metal implants in imaging diagnosis.
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Objective To evaluate the clinical application of CT perfusion in predicting the status of axillary lymph nodes in patients with breast cancer.Methods Fony-five patients with infiltrating breast cancers and 46 clinically palpable axillary lymph nodes underwent dynamic mtdti-slice spiral CT(MSCT).Semi-automatic calculation of perfusion parameters including blood flow(BF),blood volume(BV),mean transit time(MTT)and permeability surface(PS)of "target" lymph nodes and muscles in the same scan level were respectively meagured and analyzed.Nonparametric Mann-Whitney U test was used for the statistics.Results Forty-six "target" lymph nodes examined by CTP were metastasis in 32 cases and reactive hyperplastic lymph node inflammation in 14 cases at pathology.22 of 32 metastatic "target" nodes (68%)were sentinel lymph nodes(SLN).BF of CIP for inflammation and metastatic "target" nodes were (76.18±31.53)and(161.60±40.94)ml·100 mg-1·min-1,BV were(5.81±2.50)and(9.15±3.02)ml／100 mg.MTT were(6.80±1.55)and(5.50±1.84)s,PS were(25.82±4.62)and (25.96±7.47)ml·100 mg-1·min-1.There were significant correlations between the BF value of inflammation and metastatic "target" nodes(r=0.14,P<0.05)and there were no significant correlations among the BV,MTT and PS values of inflammation and metastatic "target" nodes(r=-0.03,0.05,0.07.P>0.05).Conelusion CTP can provide useful informafion for evaluating lymph node status.
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Objective To investigate CT stage of carcinoma of gallbladder and its role in preoperative evaluation of surgical resectability.Methods CT staging with reference to current literature was made retrospectively in 80 cases of carcinoma of gallbladder proved pathologically and imaging studies.Surgical resectability was evaluated in combination with surgical and pathological results on different stages of this disease.Results In this group,there were stage Ⅰin 9 cases,stageⅡ in 18 cases,stage Ⅲin 42 cases and stageⅣ in 11 cases.32 cases were radically resected,among them,9 were stage Ⅰ,18 stage Ⅱ and 5 stage Ⅲ.Palliative resection was done on 31 cases;all were stage Ⅲ.Exploratory surgery were done on 9 cases(6 stage Ⅲ and 3 stage Ⅳ),by they were unresectable.8 cases (CT stage Ⅳ on CT)had no surgery,but treated otherwise.Conclusion CT studies and staging of gallbladder carcinoma are conducive to preoperative evaluation of surgical and choice of appropriate treatment planning.
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Objective To sum up CT findings of sacroiliac joints in ankylosing spondylitis with an attempt at further improving early and even accurate diagnosis of the disease.Methods CT features of sacroiliac joints in 80 cases with anklyosing spondylitis proved clinically were analysed,and their application in making the diagnosis was evaluated.Results 73 of the 80 cases had abnormal CT findings of the joints,with different features according to different stages of the disease.In early stage,most cases were with symmetric involvement of the joints showing shaggy appearance of the articular surface with interruption or disappearance of the joint cortex,subcortical microcysts and mild sclerosis of iliac surface of joint .In advanced stage,cases were with irregularity of sacroiliac articular surfaces,showing serrated or brush-like appearance,subcortical systic destruction,sclerosis or hypertrophic changes around the joints,and pseudo-widening,irregular narrowing or even vacuumization of the joint space.In the late or stable stage,ossification of ligaments,bony ankylosis of the joints with obliteration of joint space and osteoporosis or osteosclerosis were seen.Conclusion CT study of sacroiliac joints could be helpful in making an early and even accurate diagnosis of ankylosing spondylitis as well as in clinical staging of the disease.
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Objective To evaluate the application of MSCT in diagnosing the injury of atlantoaxial joint.Methods MSCT data of 20 cases of traumatic atlantoaxial joints were analyzed,the ability of different reconstruction methods in showing the traumatic aspects were evaluated.Results Axial MSCT and in combination with reconstruction methods such as MPR and Direct 3D could distinctly depict atlantoaxial joint in full view.Conclusion MSCT plays an important role and could be the first choice of imaging examination in the detection of injury of atlantoaxial joint.